Using live explosive-propellant ammunition for firearms training has well known disadvantages. Alternative forms of compressed gas powered ammunition are available to reduce some of these disadvantages. However, realistic practice with any small arm requires the ammunition to provide sufficient energy to propel the bullets at a velocity sufficient to achieve reasonable accuracy. At such velocities metal bullets can be lethal. To reduce such dangers, plastics bullets have been proposed, but such bullets leave unwanted residues in the weapon barrel, are inaccurate in flight, and are still very dangerous.
Other forms of bullets are known, for combat games, which comprise a shell or casing of hard gelatin filled with paint, but such bullets are inaccurate in flight, have limited range and the casing can gash the skin of a target person.
The task of the invention is to provide a bullet which is stable in flight, does not damage the weapon barrel, and reduces the risks of lethal accident.
According to the present invention there is provided a bullet partially composed of metal, and characterized in that the metal is in the form of a powder embedded in a solid wax-based or wax-like matrix.
The matrix is preferably formulated to disrupt firstly upon impact with a target and secondly upon being exposed to excessive propulsion forces, so that impact damage is limited by disruption of the bullet.
Such bullets are reasonably safe for use in "war-games", "combat-games", and like operations in which the targets are persons, and the bullets are preferably used in ammunition and/or weapons which limit the muzzle energy to a maximum of about 3.5 foot/pounds (or about 0.5 kilogram meters) and preferably to less than about 2.5 foot/pounds (or about 0.35 kilogram meters) to avoid the need for such persons to wear special protective clothing. Such muzzle energy is obtained in accordance with known techniques.
The bullet may contain coloring to act as a marker upon striking a target. The coloring may either be easily removable by ordinary laundering or dry-cleaning processes; or be of an indelible or "permanent" kind which is extremely difficult to remove especially from clothing.
Such marker bullets are useful for marking selected persons, e.g. to identify a particular person in a riot or civil-disturbance.
The metal is preferably a dense metal or alloy, such as brass, copper, lead or zinc, or a mixture thereof, reduced to a powder in which the particles are less than 400 microns. The particles preferably provide at least 70% of the mass of the bullet.
The matrix preferably comprises a solid material such as paraffin wax, microcrystalline wax, polyethylene wax, carnauba wax, candelilla wax, bees wax, a wax-like hydrocarbon preparation or a wax-like silicone preparation or a blend thereof; and said solid material is preferably blended with an oily or fatty material which serves as a plasticizer to make the matrix sufficiently tractable to permit expansion of the bullet, upon firing, to engage the barrel rifling, and also to improve the behavior of the bullet upon impact with the target.
The melting or softening temperature of the solid material and the proportion of oily or fatty material may be determined to suit the ambient temperature-range of the conditions under which the bullet is intended to be used, so that at the bottom of said range the bullet does not become so brittle that it shatters upon firing while at the top of said range the bullet remains sufficiently hard to be fired without melting or becoming plastically deformed to an unacceptable degree.
The proportions of the solid material to oily or fatty material may be varied from 1:4 for cold climates to 9:1 for hot climates For example, the percentage of solid material preferably lies between 20% and 40% for polar climates, between 40% and 70% for temperate climates, and between 60% and 90% for tropical climates, the remainder being substantially the oily or fatty material and optionally a small amount of dye and/or other additive.
The density of the bullet is primarily determined by the proportion of metal, or metal and pigment powdered mixture, in the bullet. Satisfactory results can be obtained with blends in which the weight of the matrix is roughly the same as the weight of powder, provided that the matrix is formulated to suit the climatic conditions of use; but it has been found that the operational temperature range and other properties can be improved by using a relatively fine powder, preferably such as one in which most particles are less than 200 microns, e.g. 70/150 microns, and a relatively high proportion of the powder, such as 75% or more, so that a single formulation can be employed under most climatic conditions without giving rise to firing problems or, more importantly, increasing the risk of impact damage upon the target.
The matrix formulation problems posed under certain conditions (e.g. the need to compromise between the hardness required during handling, firing and flight of the bullet and the softness required for reducing the risk of damaging the target, when the latter is a live creature or person to be marked) are reduced in accordance with a preferred feature of the invention by formulating the matrix to meet the softness requirements and coating a part or all of the bullet with a harder formulation of wax-based material to provide superficial strength. Such a coating preferably has an average thickness less than 1 mm, the preferred thickness range being less than 0.5 mm e.g. between 0.2 and 0.02 mm.
The bullet preferably has a weight of less than 3 grams, e.g. about 1.5 to 2.4 grams.
The bullets are preferably made by hot blending and mixing of the ingredients and molding or casting the. bullets. The bullets may cast directly into cartridge nose-parts, which nose-parts may be separate from the bodies of the cartridges and, after casting of the bullets are attached to cartridge bodies, and preferably remain attached to the cartridge bodies during firing of the bullets; or the nose parts may be integral with the cartridge bodies.
The invention includes a method of making a bullet, for a round of ammunition comprising a hollow nose-part of a cartridge containing a propellant or chargeable with a propellant; the method including the steps of:
(a) dispersing a metallic powder in a liquid or semi-liquid settable wax-based material to form a moldable or castable composition, PA1 (b) inserting an ejectable barrier into the hollow nose-part to leave a cavity having an open front end, PA1 (c) filling said cavity with said composition and allowing or causing said composition to set to form a bullet in situ in the nose-part. PA1 (a) dispersing a metallic powder in a liquid or semi-liquid settable wax-based material to form a moldable or castable composition, PA1 (b) pouring or injecting composition into molds, causing said composition to set and removing the set molded or cast bullets from the molds, PA1 (c) chilling the bullets; and PA1 (d) dipping the chilled bullets into a molten wax-based material to at least partially coat the bullets, with a coating which, upon solidification, is harder than the material in the set composition.
The invention includes a bullet and nose-part device made by said method; and includes a device or cartridge comprising the bullet and a hollow nose-part, which nose-part substantially contains the bullet and is integral with or is releasably securable to a cartridge body.
The method may include the further step of coating the exposed front surface of the bullet with a wax-based material.
The invention also provides a further method of making bullets, for insertion into cartridges or into a weapon, comprising the steps of:
The invention includes a bullet made by said further method.